To the Editor,
We appreciated the paper of Alizade et al. (1) entitled ‘’Percutaneous closure of a secundum atrial septal defect through femoral approach in an adult patient with interrupted inferior vena cava (IVC) and azygos continuation’’.
The authors clearly highlighted that interventional endovascular maneuvers normally coded for vascular access, materials, and technique, must be carefully re-evaluated in the preoperative planning, in case of congenital anomalies involving the systemic venous return to the right atrium.
Congenital anomalies of the deep thoracoabdominal venous system are caused by variations in the development during embryogenesis. Azygos continuation of the IVC, like the case described by the authors, is a very rare venous variant. It is characterized by the absence of the IVC segment between the renal and hepatic veins. Therefore, blood from the IVC segment is drained into the thorax by the azygos vein, while hepatic veins are directly connected to the right atrium (Fig. 1-3) (2). Generally, azygos continuation is clinically silent and is often incidentally recognized during imaging studies done for other clinical purposes. Multidetector computed tomography is the first-line noninvasive diagnostic method for characterizing the vascular anatomy and its anomalies (3). So, any possible venous variant, including azygos continuation, has to be detected in the preoperative setting of conventional thoracoabdominal surgery and percutaneous endovascular venous and cardiac procedures to plan the most suitable therapeutic approach (1-4).
Figure 1.
Contrast-enhanced multidetector computed tomography axial (1), coronal (2), and Sagittal (3) multiplanar reconstruction that shows the congenital anomalies azygos continuation of the inferior vena cava, with a dilated azygos vein (AV), normal superior vena cava (SVC), and hepatic vein (HV) of the liver (L) connected directly with the right atrium of the heart (H)
Figure 3.
Contrast-enhanced multidetector computed tomography axial (1), coronal (2), and Sagittal (3) multiplanar reconstruction that shows the congenital anomalies azygos continuation of the inferior vena cava, with a dilated azygos vein (AV), normal superior vena cava (SVC), and hepatic vein (HV) of the liver (L) connected directly with the right atrium of the heart (H)
Figure 2.
Contrast-enhanced multidetector computed tomography axial (1), coronal (2), and Sagittal (3) multiplanar reconstruction that shows the congenital anomalies azygos continuation of the inferior vena cava, with a dilated azygos vein (AV), normal superior vena cava (SVC), and hepatic vein (HV) of the liver (L) connected directly with the right atrium of the heart (H)
References
- 1.Alizade E, Karaduman A, Balaban I, Keskin B, Kalkan S. Percutaneous closure of a secundum atrial septal defect through femoral approach in an adult patient with interrupted inferior vena cava and azygos continuation. Anatol J Cardiol. 2020;23:188–91. doi: 10.14744/AnatolJCardiol.2019.70968. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Oliveira JD, Martins I. Congenital systemic venous return anomalies to the right atrium review. Insights Imaging. 2019;10:115. doi: 10.1186/s13244-019-0802-y. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Rossi UG, Rigamonti P, Torcia P, Mauri G, Brunini F, Rossi M, et al. Congenital anomalies of superior vena cava and their implications in central venous catheterization. J Vasc Access. 2015;16:265–8. doi: 10.5301/jva.5000371. [DOI] [PubMed] [Google Scholar]
- 4.Vurgun VK, Candemir B, Altın AT, Akyürek Ö. Management of scar-related atrial flutter in a patient with dextrocardia, inferior vena cava interruption, and azygos continuation. Anatol J Cardiol. 2018;19:148–9. doi: 10.14744/AnatolJCardiol.2017.7950. [DOI] [PMC free article] [PubMed] [Google Scholar]